New concept for transporting stranded and remote gas:
An explorer having mid to small size gas reserves (8TCF and less) that are located in remote
locations must have access to a pipeline transportation system. If not, their gas is stranded. To be
able to drill up and bring on the production the explorer must realize an acceptable wellhead
netback (or how much he gets) for his gas. The producer must also be able bring on his gas
production with the least capital expense. With rising field development costs, the explorer faces
serious challenges to get his field developed in a timely manner and within budget.

In receiving the gas, the market also faces significant challenges, that of rising receiving terminal
costs, environmental issues and a flexible and reliable source or sources of gas supply having the
lowest transportation cost possible. Leading gas explorers now developing a marine gas
transportation system (CGLC) that not only provides the needed wellhead netback but also allows
the explorer to produce and deliver the full value of his gas production to market.

Natural gas represents a source of clean energy for which global demand is increasing. Over
three-quarters of the world’s known offshore reserves of natural gas remain undeveloped due to
the high cost of transportation.

These reserves are found in far off and remote locations as gas
pools or gas associated with to oil production. The size of these pools is often substantial
(typically 8.0 TCF and below), yet they remain below the critical size required for the economics
demanded for new long-term maritime LNG development.

LNG requires large capital needs and considerable process energy to achieve feasibility.
Upstream capital costs are in the billions of dollars (US$) to establish the LNG liquefaction
facilities. Additional capital expense is required at the market end to set up receiving terminals for
re-gasification. There are separate and additional capital costs required to produce and deliver
the LPG’s to market. Long lead times and considerable community opposition to receiving terminal locations or expansion in market areas
have only served to focus industry on the returns of the largest of these gas fields.

Fig:LNG carrier underway

Overall, a LNG ship carries natural gas product under storage conditions at a volumetric ratio of
approximately 600 times that of the product at STP conditions. This is achieved with storage
conditions of -260°F (-162°C) and atmospheric pressure. Large ships of this type carry
approximately 3.0 BCF and more of natural gas.

Specific distillates of natural gas, Butane and Propane, both also produced from crude oil refining,
are gaseous at ambient temperature and pressure and yet are liquid when stored and transported
under modest pressure or in a moderate refrigerated state (hence the name LPG).

Specialised
LPG ships have been developed to utilise these particular properties, being either pressurised,
fully-refrigerated, or semi-refrigerated (trade as both pressure and refrigerated storages)
containment systems.

Fig:CNG ship at sea

Compressed Natural Gas (CNG) has also been developed as a shipping concept, relying on the
high pressure containment technology used in conventional pressure vessel CNG storage and in
pipeline systems to provide a form of concentrated gas storage which can be fitted onboard ships.
The CNG concept that has been around for a long time, seeks to offer savings by removing the
need for the expensive onshore refrigeration trains required for LNG.

However, CNG still needs
separate gas conditioning and process systems to get the production gas segregated and suitable
for transportation. A separate LPG processing and transportation system is also needed.

When circumstances allow it,
pipelines provide the best option for transporting gas over short
distances, while Liquefied Natural Gas carriers offer various
advantages for large quantities of natural gas to be transported
over long distances.

With the innovative concept of the Coselle CNG
Carriers, which utilize Coselles, a new technology consisting of
large coils of pipes wound into a cylindrical storage container to
contain compressed natural gas, gas producers are being offered an
economically optimal solution for the transportation of moderate
volumes of natural gas over medium distances.

Thus, the Coselle CNG
carrier is the first method supporting this segment of the marine
gas transportation market that is not economically served by
pipelines or LNG ships.

The CNG carriers will provide the market with a safe, reliable and
cost effective method to transport natural gas by sea and also
deliver natural gas to underserved markets.

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